How to Easily Migrate Your Already Existing App to Flutter?

November 18, 2022

There are many reasons to migrate an existing app to Flutter. By doing so, you can streamline development processes, reduce development time, and increase the efficiency of your company.


Google released Flutter in 2018, a software development kit and user interface framework designed to make creating stunning mobile apps quicker and simpler. With Flutter, you can use a single codebase to create cutting-edge, high-caliber apps for Android, iOS, Windows, Linux, Mac, and Web platforms. Flutter apps work flawlessly on all leading mobile platforms, run incredibly quickly, and have fantastic looks.

But why would I need Flutter if I already have Android and iOS apps? To save time and to save money on app development, of course. 

Flutter provides unique features to assist developers with regular and simple tasks. Therefore, Google has enabled businesses to use Flutter with their native apps without having to rewrite their software in Flutter completely. If you do not wish to do it yourself, you can also hire Flutter developers to initiate the transfer of your existing app.

Table of Content
Why Flutter?
Deciding When to Opt for Flutter?
Why Flutter is most preferred?
How to migrate app to Flutter?
iOS and Android App
Prime Example

Why Choose Flutter for converting the current Android or iOS app

Flutter is a cross-platform, open-source framework created by Google and uses Dart as the programming language. There are many hybrid frameworks for app development, but Flutter since its inception has been the most used and loved framework.  It is relatively adaptable and enables developers to create cross-platform scalable, reliable, and fully functional apps. Flutter introduced the add-to-app functionality in 2019. With the help of this technology, we may integrate the entire Flutter app or certain sections into an already-existing iOS or Android app. You can smoothly convert your iOS or Android app to Flutter without sacrificing speed.

But When Should You Opt for Flutter for App Migration? 

  1. Whenever an update is required for an existing program on Android or iOS.

Let’s think about the first scenario. It’s time for a significant upgrade or redesign of your software, which is available for iOS and Android. Now is the perfect time to use Flutter. Since you need one development and a QA team rather than two, using this cross-platform software development kit will allow you to cut your development team in half. Your second resource team may have more time for other projects.

Further, development resources are typically more efficient than native language development. This results in resource savings as compared to the conventional native language method. Code size and runtime efficiency are equivalent to native language apps.

  1. Even though there are technical problems with your current app, you still need to work on issuing an update.

In the second scenario, you need to revamp as you face some technical issues and need to work on the update; your hands are full with the tasks.  Should you utilize a Native app language, such as Swift or Kotlin, or should you consider using Flutter? A flutter is a great option in such a case. Both apps will have the same design and feel. As Flutter has an easy learning curve and a large community for support, developers can quickly resolve issues compared to other platforms. It provides all maintenance and development benefits of being truly cross-platform.

  1. When you want to add a new feature to your existing app

There is some uncertainty about the final case. You wish to add functionality to two natively created apps that don’t yet require replacement or significant improvements. Flutter should remain your option, though. While creating your new features in Flutter, you can continue using your old native-language code.

Why Is Flutter The Most Popular Choice For App Development?

Flutter over other hybrid frameworks
  • Its simplicity in design, the Flutter app’s performance, and quickness
  • Single code base so you build two apps for Android and iOS simultaneously; the app just needs to be tested once.
  • It offers all the features and functions needed for speedy mobile app development.
  • Thanks to the Hot Reload functionality, we can immediately see the changes made to the source code.
  • You should use Flutter to address a unique set of issues. 

How can you import your current app into Flutter?

First, Flutter must be incorporated as a library or module. That module must reflect the UI of the app. Using the Flutter create-t module command, you can create a module. This will start building a new project with a somewhat different structure. This method of creating a module allows you to divide the main code from the Flutter code. It serves as an external dependency for this module. The next step was the same as outlined in the official Flutter documentation.

Adding Flutter to an Android app or an iOS app already in use

  1. Open the current project.
  2. Make a new Flutter Module wizard.
  3. If you want to migrate an Android app, then use the Android Flutter APIs. and if you want to migrate an iOS app, then install CocoaPods and use Flutter iOS APIs.
  4. Build and run
  5. Attach and hot reload.

What Flutter enables us to do when incorporated into the Android app

  • To auto-build and import the Flutter module, you can add a Flutter SDK hook to your Gradle script.
  • Build your Flutter module into a generic Android Archive (AAR) to improve Jetifier interoperability with AndroidX if you want to integrate the Flutter module into your own build system.
  • Use the FlutterEngine API to start and maintain your Flutter environment independently.
  • You can edit Android and Flutter projects in Android Studio using the module import/creation wizard
  • Both Java and Kotlin-built apps are supported.
  • An IDE or command line can use Flutter to attach a function to connect to a Flutter app and debug it. It can also reload the app using stateful hot reloading.
  • The pre-existing platform can be coupled with Flutter plugins to allow Flutter modules to communicate with it.

Actions that Flutter enables when incorporated into iOS apps

  • For the Flutter module to automatically compile and be imported, add a Flutter SDK hook to your CocoaPods and Xcode build phase.
  • You can construct a Flutter module into a basic iOS Framework and then incorporate it into your own build system.
  • Without attaching a FlutterViewController, you can start and maintain your Flutter environment using the FlutterEngine API.
  • Moreover, it supports Swift and Objective-C for iOS apps.
  • Allow Flutter plugins to be used by Flutter modules to communicate with the platform.
  • You can connect to a Flutter-containing app and debug or reload it using a stateful hot reload by using the Flutter attach function from an IDE or the command line.

Example of Flutter Migration

Google Pay

Google Pay, an example of migrating existing app to Flutter

With 100 million users across dozens of nations, Google Pay enables users to save money, pay bills, and more. But to achieve that, they had to rely on 1.7 million lines of code across their Android and iOS apps, which felt unsustainable given that Google Pay was still expanding to new nations, each of which would need its unique features.

The fact that their existing consumers were nearly entirely Android users while many of those new locations had a significant percentage of iOS users added to the difficulty of the situation. As a result, they would have to retain more iOS engineers and build each feature twice.

Instead, they decided to spend money on Flutter, a cross-platform framework that would help them accomplish more with less.


Apps created with Flutter are sharper and more precise than those made with the Android or iOS programming language. The transition to Flutter happened rather quickly. It is simple for developers to port native apps to Flutter because of the Hot reload and Ahead of Time compilation features. You can always get in touch with us if you need more information on developing apps with Flutter. Flutter is the future, and now is the ideal time to begin creating apps with it.


Jinesh Shah



Recent Post

Recommended Blogs